Civic EG

i have a 93 civic hatchback with a d15. the transmission shift shaft seal is leaking. i bought a new seal and it looks the same as the old one but is a tiny bit bigger. it will not fit inside the transmission without tearing the outer edge of the seal. is there a trick to installing it? because the part #221607 is the only one for this car. any ideas???

Not familiar with replacing them but is it all ruber or does it have a metal ring inside of it?