Trim the soft weather stripping at the top of the side pieces at about a 45 degree angle so the top and side pieces overlap nicely.
How to cut garage door seal.
Hold each of the side pieces in place and nail them in the same fashion as you nailed the header piece.
Clean the door bottom photo 2 then cut the new rubber seal to length with a razor knife.
Now temp nail the top seal to the jamb you want the inside edge of the pvc portion to be even with the inside edge of the jamb.
Be patient it takes a lot of pushing and pulling even with a helper.
If you have a wooden garage door rip off the nailed rubber seal.
Thread the t shaped edges into the weather seal track then slide the seal across the door.
Door sweeps come in standard sizes but if you cannot find one.
Measure and cut the side pieces so they touch the header piece and extend to the garage floor.
Put enough temp nails in to hold the seal up against the jamb.
In this episode dave mars shows how to better insulate your garage door to help save energy and money.
When the door opens the rubber flexes so as not to be an impediment and when the door closes the rubber provides a strong air seal.
New weatherstripping comes in rolls and you can easily cut it to length with a utility knife.
This video explains how to remove and replace the rubber seal at the bottom of your garage door.