Problem: Leaking Faucet on Bathtub Handle
Cause: Worn gasket seats and springs & damaged cartridge
Solution: Replace parts

Parts:
Delta Faucet Stem / Cartridge Replacement - RP25513 - $13.67
Delta Seats and Springs replacement - Delta 0-3019 - $3.00

Tools:
-Hammer
-Pry Bar
-Allen Key