Install the new seal with the larger sloped edge to the outside of the garage door and the flat part against the bottom of the door.
How to install bottom garage door seal on metal door.
Thread the t shaped edges into the weather seal track then slide the seal across the door.
In this video we add a new aluminium retainer and new rubber seal.
Clean the door bottom photo 2 then cut the new rubber seal to length with a razor knife.
Tips on replacing your garage door bottom seal.
He also gives a brief description.
If you have a wooden garage door rip off the nailed rubber seal.
Be patient it takes a lot of pushing and pulling even with a helper.