Break up 2Al + 3Pb - 2Al + 3Pb into two half equations- one for oxidation and one for reduction

oxidation:

Al(s) --> Al^3+(aq) + 3e
reduction:
Pb^2+(aq) + 2e --> Pb(s)
reaction:
2Al(s) + 3Pb^2+(aq) ==> 2Al^3+(aq) + 3Pb(s)