Reconnecting extruded mesh parts? /filling in holes

so im sculpting a horse and i accidentally extruded some parts instead of copying them and proceeded to save & close… now i still have the parts kinda in place but cant reconnect them to work properly… i still want to be able to sculpt over it and continue editing, even if i had to recreate the details, i dont mind…)

i tried:

  • boolean modifier (changed the extruded part into uneditable horrible polygon, neither operation worked)
  • ctrl J joining the extruded parts with the original mesh (nice, but when i sculpted over it it created holes on sides where the two parts were supposed to connect)
  • F filling (failing in all ways possible)
  • i wanted to try the W - delete doubles i found about but i cant find the new context menu since W doesnt bring it up anymore
  • filling the holes without the extruded parts but i wasnt successful either…

( im really new to Blender, if you know the solution, elaborate the steps for me, please, i get lost easily )
heres the file:

You were close:

  • CTRL-J to join the meshes together
  • Select all and use ALT-M (Merge), choose By Distance - this is the old “Remove Doubles”

I also noted the section on top of the head is masked when joined. You can remove the masking with the Mask tool - change to “-” and paint it out. (the + and - is next to the strength in the top bar).

thank you! i already solved it by filling the polygon and then hit remesh so it added faces to the polygon but im glad i know how to remove doubles now thanks to you :>