I have update a system from RetroPie 4.7.1 to 4.8 without issue. Better configure the system after the update to 4.8.

Once again,I suggest using PINN. It is basically just a bootloader that lets you download various operating system directly and offers an bootmenu.
There are two minor problems though.

You can't define the partition sizes from the GUI, there is a webpage here where you can do that beforehand. The image for RetroPie is not official, so asking for future support might be difficult. But I had no issues while using the image so far.

ok, i will make a backup and start the installation. probably will be back later to cry for more help.

@FluffySpikes im on the latest version of RetroPie and on kodi 16. I tried 17 but I didn't liked it, so I reinstalled a backup. The missing controller support is not a problem for me, since I prefer to use my tablet to control Kodi.