How to remove solidify when apply

I am working for the first time in blender and i try to make object for 3d print.

i have apply solidify but i want to change the thickness.
my to mech look are not touching they can be consider as tow objet but they are one.
i will like to delete the incise and restart the solidify.



my forme is complex. it will be to long to dealeat part by part and i am not able to selec just the incide part .

thanks for any help

max

Delesect everything > click L (while holding over the mesh) > CTRL + I to invert (if nessasary) then X and delete.

pressing L will select everything that is “linked” to whatever you you use it on. so UNLESS there is a connection between the two layers, only one of them should be selected.

thanks for that

you can use weld modifier