First step, put your puller away. All you're going to do with it is ruin things. A puller is never required for this job. There is nothing holding that lower gear on, except possibly rust or corrosion. Use a small hammer and gently tap it to break it free. Do not hit the gear hard or you will chip a tooth. A gentle tap is all it takes. The gear will probably fall off right in your hand or on the ground.

Be sure to note the position of the washers. They must go on the same way.

As for seals, they can be tricky and I don't have any good advice other than to make sure you get them started evenly. You don't want to get the sealing (inside) lip to bend over... in really difficult cases I use a pick or small finish nail VERY CAREFULLY to get the inner lip to go over the shaft. Once it's started then use a socket (I prefer PVC pipe fittings) and a small hammer to drive the seal into place. It is not possible to get one side started and then try to get the other side started. It must all go in at once.

Good luck!

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Matt L. -- Cary, NC -- '89 740 sedan -- '91 740 wagon