Normally the oil seal can be eased out with a screwdriver or suchlike. sometimes the plunger can be extracted with a pair of long nose pliers. If not you can make a tool which clamps on the spindle and can them be gripped in vice of pair of molegrips to ease it out. I have added a picture showing the dimensions of such a tool or you can borrow mine if you still have need of one. Contact me by pm so we can sort out details.