There are two basic types of garage door openers chain driven and belt driven.
How to install a replacement garage door opener.
When buying a garage door opener choose a 1 3 hp or 1 2 hp garage door opener for a single garage door 1 3 hp can be hard to find at some home centers.
Go with 1 2 hp for a double door and 3 4 hp for a door that has a wood or faux wood overlay they can be heavy.
Mount the new motor in the same location as the old one.
Some brands may work with even older door opener units.
This home depot guide will explain the cost to install garage doors and openers or replace existing ones so you can decide which options are best for your budget.
A belt driven garage door opener can be a bit quieter during operation.
Both operate in roughly the same way but just use a slightly different part for operation.
Choose a garage door opener.
If your opener model is no longer manufactured it may not be easy to find a new remote designed specifically for your opener.
Install the end of the rail in the bracket that held the old opener above the garage door and secure it with the fastener bolts or clevis pin.
Consider this when making the choice of what opener to buy.