[quote=@Diabolicalrhapsody]
[@TheUnknowable] I want you to assign a difficulty rating to Mia's attempt on installing another core on the damaged droid that were left from their initiation/practice tests and roll my Tinkering skill for it if you could please.
[/quote]

ok.  I'll say it's moderate difficulty (15), since it's a complex part but an old design, so it's not as complex as the newer droids.  Also, your are combining two damaged ones into one working one.  I actually rolled 3-4-5-6 (weird), so that's 18.  A success.