THX @Manoj
I already started - will take some time…
And is there any possibility to add something in Install /e/ on a LG G3 (International) - “d855”
The rooting guide is not very helpful - the D855LafToolkit v4.00 from here [How-To & Skript] Root, Custom-Recovery, Unlock & Bump: LG G3 Toolkit – Android-Hilfe.de makes it very easy