There are two types of garage door springs, and one is more dangerous than the other when it comes to replacing them.
If there is a single spring enclosing a shaft that spans the top of garage door opening then you have a torsion spring, and these are the more dangerous ones for a DIYer to replace because it has to be wound tightly enough to lift the weight of the door.
If your door has a spring on both sides of the tracks that guides the door overhead then you have extension springs that stretch when the door is closed. These can be safely & easily replaced when the door is open (make sure the door is somehow locked/blocked open and can’t close by accident). The springs should be under no tension at all when the door is open.
There are two types of garage door springs, and one is more dangerous than the other when it comes to replacing them.
If there is a single spring enclosing a shaft that spans the top of garage door opening then you have a torsion spring, and these are the more dangerous ones for a DIYer to replace because it has to be wound tightly enough to lift the weight of the door.
If your door has a spring on both sides of the tracks that guides the door overhead then you have extension springs that stretch when the door is closed. These can be safely & easily replaced when the door is open (make sure the door is somehow locked/blocked open and can’t close by accident). The springs should be under no tension at all when the door is open.