Garbage disposal installation: DIY or hire

A swap onto the same mount is a different job than a first-time install. Pick the one you actually have.

DIY if the hard parts are already there

Same opening, same mount brand, power already at a dedicated wall switch, and you have done a drain kit before. Kill power. Support the old unit. Transfer the discharge tube and dishwasher hose. Seat the new unit on the mounting ring until it locks. Run water before you load food.

Hire if any of this is new

New circuit. New sink hole. A dishwasher tie-in you have never done. A rusted mount that will not break free. Or you do not want a slow leak into the cabinet tomorrow. Installation is cheap compared with a swollen floor.