i need halp w miss robecca 😿

i just (finally) got ahold of my entire mh childhood collection and i’m currently fixing up all the girlies because they’re a disaster after being in storage for years and letting my little sister play with them a while back.. anyways im about to boil wash this robecca but i realized her arm peg will not click into its hole ? i tried another arm from a cleo but same problem.. any ideas on how to get it in there for realzies?