you have an odd definition for "easy" I think.
garage door springs are safe if you are careful and you use the correct tools and procedures. the instant you take a shortcut with these, you increase the likelihood of a bad outcome.
so, don't take shortcuts, and don't do the work if you don't know what you're doing.
the professionals know this and that's why we pay them, but they're not special creatures with special abilities; they're people who understand that this is a situation which can bite you, and they act accordingly.
Just about anyone can change their garage door springs, if they do so correctly.
