How to Rip Sims 4 Character to Replace Protagonist in GTAV?

[SilentCharm]

I've only just downloaded GTA V and have no experience with modding a game like this and will probably need any explanations to be fairly simplified so heads up!

I've seen female Sims 4 PEDS available for download on the web that replace either Franklin, Michael or Trevor, along with a playable Ellie from TLOU that seems to have been rigged to have guns and cars fit her size.

I wanted to create a PED of one of my child sims for GTA (with multiple outfits - I'm a bit of a roleplayer and want clothes for different weathers) because the idea of playing as a kid that can get a 5 star wanted level or shoot things up with rockets seems hilarious to me, I've found a grand total of nothing on how to replace a GTA protag with a Sims character or how to rig them to fit weapons and whatever else requires it though.

If someone with knowledge of ZModeler could help out or send some links my way that would be very much appreciated! P.S. Sorry if I've posted this in the wrong place, having a bit of trouble navigating the site.

Side Note: Programs I have include ZModeler, SimRipper, 3D Ripper DX (can't seem to get this one working), Blender and GIMP. I've read that Blender won't be much help as it's incompatible with the GTA PED models though.