If you need assistance I encourage you to join my Discord at:
https://discord.gg/YZx5NjGJyF
XAT Download:
https://github.com/AsgardXIV/XAT/releases
Midlander M SKLB path:
chara/human/c0101/skeleton/base/b0001/skl_c0101b0001.sklb
0:00 Intro
1:20 Export PAPs
2:42 Extract SKLB
4:35 Replacing Animations
source