How to delete inner faces of a body covered by a clothing, merging it with the skin?

Hi, I am a … Medium beginner.
I have a 3d model of a girl with many items and clothes, and some nude parts. The clothings are around the skin and not part of the same vertex group. Now I want to estrude the borders of the clothings inside the skin and to merge the skin with the clothes, deleting the interior faces, to have a unique model. I’ve tried with the modifiers to subtract the tshirt with the body, and yes I obtain something, but still the skin inside the clothings exists and it isn’t deleted. How can I proceed? Should I use Solidify (with Apply) and then subtract in this way, while the clothings are “incapsuling” the skin?
Or… how?

select what is not visible inside and delete it !

show some pics for what you mean

happy cl

Unfortunately, the t-shirt has another vertex disposition than the body. I’m already able to select the faces and to delete them! But I want to cut the skin where the clothes’ borders are.

try to use the V command to rip it

but might need to add some verts to complete the whole section !

happy bl