Problems Putting in the selector shaft seal

Can I drill the floor board and drive the seal in through the top of the car? It has no carpet. Then just plug the hole. Going to look at this tomorrow

When I parked the car for a week or so. The fluid all leaked out. I don't know where from but I'm guessing it came from one of the two seals on the shifter shaft.

i have the seal out. The transmission is still in the car. In its original place. I didn't want to move the exhaust down.

The valve body is out.

I'm having a hard time getting the new seal back in. I've already ruined one.
I tried putting it in with a socket and clamp. It went in crooked but I was able to get it back out fine. It was that crooked.

Tried using a large bolt with well fitting washers and a nut to tighten it in.
Some how it crush the top of the seal.

It's a 904 in a dart.

Also.......I bought a new seal for tomorrow. It's duaralast 8906.

It didn't some with the inner seal for the kickdown shaft. I got that with a little kit that included both seals

It's taller than the original. How much will this matter? I think it will be fine.