I do that every morning by graphic tool.
now:
apt update
Get:1
http://deb.debian.org/debian stretch-updates InRelease [91.0 kB]
Ign:2
http://dl.google.com/linux/chrome/deb stable InRelease
Hit:3
http://security.debian.org/debian-security stretch/updates InRelease
Get:4
http://dl.google.com/linux/chrome/deb stable Release [943 B]
Hit:5
http://security.debian.org buster/updates InRelease
Ign:6
http://deb.debian.org/debian stretch InRelease
Hit:7
http://deb.debian.org/debian stretch Release
Get:8
http://dl.google.com/linux/chrome/deb stable Release.gpg [819 B]
Get:9
http://cdn-fastly.deb.debian.org/debian buster InRelease [150 kB]
E: Repository 'http://dl.google.com/linux/chrome/deb stable Release' changed its 'Origin' value from 'Google, Inc.' to 'Google LLC'
N: This must be accepted explicitly before updates for this repository can be applied. See apt-secure(8) manpage for details.
Do you want to accept these changes and continue updating from this repository? [y/N] y
Get:11
http://dl.google.com/linux/chrome/deb stable/main amd64 Packages [1,130 B]
Get:12
http://cdn-fastly.deb.debian.org/debian buster/main amd64 Packages.diff/Index [27.9 kB]
Get:13
http://cdn-fastly.deb.debian.org/debian buster/main Translation-en.diff/Index [27.9 kB]
Get:14
http://cdn-fastly.deb.debian.org/debian buster/main amd64 Packages 2018-11-08-1415.23.pdiff [482 B]
Get:14
http://cdn-fastly.deb.debian.org/debian buster/main amd64 Packages 2018-11-08-1415.23.pdiff [482 B]
Get:15
http://cdn-fastly.deb.debian.org/debian buster/main Translation-en 2018-11-08-1415.23.pdiff [183 B]
Get:15
http://cdn-fastly.deb.debian.org/debian buster/main Translation-en 2018-11-08-1415.23.pdiff [183 B]
Get:16
http://cdn-fastly.deb.debian.org/debian buster/main amd64 DEP-11 Metadata [3,719 kB]
Get:17
http://cdn-fastly.deb.debian.org/debian buster/main DEP-11 48x48 Icons [3,625 kB]
Get:18
http://cdn-fastly.deb.debian.org/debian buster/main DEP-11 64x64 Icons [7,320 kB]
Get:19
http://cdn-fastly.deb.debian.org/debian buster/main DEP-11 128x128 Icons [12.0 MB]
Fetched 26.9 MB in 1min 23s (324 kB/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
10 packages can be upgraded. Run 'apt list --upgradable' to see them.
then
root@debi:/etc/apt# apt list --upgradable
Listing... Done
xserver-xorg-core/testing 2:1.20.3-1 amd64 [upgradable from: 2:1.19.2-1+deb9u2]
xserver-xorg-video-amdgpu/testing 18.1.0-1 amd64 [upgradable from: 1.2.0-1+b1]
xserver-xorg-video-ati/testing 1:18.1.0-1 amd64 [upgradable from: 1:7.8.0-1+b1]
xserver-xorg-video-fbdev/testing 1:0.5.0-1 amd64 [upgradable from: 1:0.4.4-1+b5]
xserver-xorg-video-intel/testing 2:2.99.917+git20180925-2 amd64 [upgradable from: 2:2.99.917+git20161206-1]
xserver-xorg-video-nouveau/testing 1:1.0.15-3 amd64 [upgradable from: 1:1.0.13-3]
xserver-xorg-video-qxl/testing 0.1.5-2+b1 amd64 [upgradable from: 0.1.4+20161126git4d7160c-1]
xserver-xorg-video-radeon/testing 1:18.1.0-1 amd64 [upgradable from: 1:7.8.0-1+b1]
xserver-xorg-video-vesa/testing 1:2.4.0-1 amd64 [upgradable from: 1:2.3.4-1+b2]
xserver-xorg-video-vmware/testing 1:13.3.0-2 amd64 [upgradable from: 1:13.2.1-1+b1]
upgrade
root@debi:/etc/apt# apt -s upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
The following packages were automatically installed and are no longer required:
0ad-data 0ad-data-common cpp-6 fonts-sipa-arundina fonts-texgyre gcc-6 guile-2.0-libs libasan3 libavcodec57
libavutil55 libbind9-160 libcfitsio5 libdns1102 libenet7 libevent-2.0-5 libgcc-6-dev libgles2-mesa libgloox17
libiodbc2 libipt1 libirs160 libisc169 libisccc160 libisccfg160 libjsoncpp1 libkf5akonadiprivate5abi1
libkf5calendarcore5abi1 libkf5mimetreeparser5 libkf5syndication5 liblwres160 libmbedcrypto1 libnvtt2 libperl5.26
libplacebo5 libpoppler64 libpoppler74 libprotobuf-lite10 libpython3.5 libpython3.5-minimal libpython3.5-stdlib
libqrencode3 libsoprano4 libswresample2 libtidy5 libva-drm1 libva-x11-1 libva1 libvpx4 libwayland-egl1-mesa
libwebpmux2 libwxbase3.0-0v5 libwxgtk3.0-0v5 libx264-148 libx264-152 libx265-160 libx265-95
linux-compiler-gcc-6-x86 linux-kbuild-4.9 manpages-fr manpages-fr-extra openjdk-10-doc perl-modules-5.26
python-blinker python-cffi-backend python-enum34 python-jwt python-pyasn1 soprano-daemon xfonts-thai-etl
xfonts-thai-manop xfonts-thai-poonlap xfonts-thai-vor
Use 'apt autoremove' to remove them.
The following packages have been kept back:
xserver-xorg-core xserver-xorg-video-amdgpu xserver-xorg-video-ati xserver-xorg-video-fbdev
xserver-xorg-video-intel xserver-xorg-video-nouveau xserver-xorg-video-qxl xserver-xorg-video-radeon
xserver-xorg-video-vesa xserver-xorg-video-vmware
0 upgraded, 0 newly installed, 0 to remove and 10 not upgraded.