It will take some doing, but it's doable. It's best to work inside an a warm area. (Let the seat sit inside over night) Then use a hair dryer to heat the seat upholstery especially in the areas you have problems with... it's much more playable when it's nice and warm.

Then you'll have to use your body weight, and work to streach it tight... and or have some one help hold it in place while you hog ring it...

Make sure the foam is in place just right, and keep working at it... just take your time...you'll get it!

Brett - 67 Drop Top 455!
http://firstgenfirebird.org/show/closeup.mv?CarID=129