Heat the joint with a heat gun (not a flame) to soften the glue, then twist gently with pliers. Cut and replace if necessary.

Compression fittings use a ferrule and nut for a tight seal (ideal for water lines), while push-to-connect fittings snap into place (no tools needed, great for quick repairs).

Wrap threads with Teflon tape + pipe dope, or use a thread repair kit (like Heli-Coil) for a permanent solution.