don't believe you. Fresh install needs more than an hour

even for a professional, needs more than an hour for a fresh install. Some may need a helper for track install. Needs strength and skil to adjust the spring.

 

If you do it the very first time and fresh install, won't believe you have the skill to install it. Even reading the manual will cost you much time.

 

声明，本人 very 能动手，没敢试过。