you need to find doctor who can replace your limbs.
P.S.
Idk bag or feature but after i get 3-rd arm with Ensis mission i try to replace it with better one but my 3-rd arm just disappear and doctor make different operation...
He replace my leg with arm so now i have 3 arms and 1 leg . And 1 minor problem. Now i have only 1 slot for boot and 3 arm slots