hi, i'm new with objects modding . I want to extract a maxis object's GMDC,rework it in Mshake & overwrite it without changing any textures. I've done this with cc objects for my game however,I'm not sure how to do this with maxis objects without messing thing up. Can I get a little advice please. Thanks a lot.

Create a package with the original GMDC in it, then export the mesh, do your stuff and reimport it. Don't change the name or TGI of the original GMDC and it will override the game one.

Alright ,if I understand this making a package means I make a recolor & using pjse tool to extract all the parts like i do with sims&their clothes. right? I don't mean to sound like that but exporting the mesh,,does it mean the same as extracting it? &shouldt it be in obj. format. I'm so new with objects&stuff since I've only worlked with sims&clothes mesh a bit& have made some paintings for the game. can you please clarify a bit. thanks in advance for your help.

If you want to change the mesh then no, you don't make a recolor. Recoloring will only pull the textures to create a new recolor, not any type of replacement.

Clone the object in object workshop with all boxes unticked in SimPE. Then delete all resources except the GMDC that has the mesh. In the bottom plugin view select (tickboxes) which mesh parts to export to change and click the Export button. That will export as .obj which you can then edit in you 3d editor. When done click the Import button in SimPE and browse to the .obj mesh you changed in your 3d editor (same one you exported before).

Thanks a lot, I will try this. It sounds easier than i thought.