I have a leak there as well. Been told there is a seal removal/installation tool specifically for this job, allows you to remove/replace seal without removing pan. Been told trans shops may have one avail
The hard way is to remove the Pan & Shift internal Shaft/Linkage, then drive the Seal out.
Easy way is to buy/rent the special Seal Remover/Installer tool. Just have to remove the external Shift lever bracket.
I was able to pull mine using a small packing tool, looks like a screwdriver with screw threads on the end. Twist it into the seal and give it a yank. Don't see why a #8 screw and a pair of vise-grips wouldn't work the same...