Here's something I wrote over on the Museum about Peregrine sealed axles:
The axle had collars on both inner end for the bearings to sit against whilst they're in the cups on the hubs. To get them out you have to hit one end of the axle which will eventually knock out one bearing, if you're axle is already knackered just smack the end - if you want to do it without knackering the axle stick an axle nut (that you don't want) on the end of it and hit that. Or use a rubber mallet.
Here's a piccy of both front and rear Perry sealed axles (the top one has King cones on it) so you get the idea - note the 'collars' on them that go either side of the inside of the bearings:
If the bearings are shot and you need to remove both, after geting one out, put the axle back in and hit the other bearing out. You can buy replacement bearings (look at the bearing code written on the bearings rubber seals and eBay search for them) for a quid each. You can also still buy replacement axles - Rini Enterprises, Standard Byke Co and some other places sell them, and it'll be cheaper than getting one made up from scratch.
When replacing the bearings, lightly grease the 'cups' on the hubs that the bearings sit in, you'll need to use a socket from a socket set that it the same diameter as the OUTSIDE metal ring on the bearings (if you tap them back in using the middle of the bearing it'll knacker the bearings) and that the socket doesn't touch the black rubber seal on the bearings. Pop one back in, then the axle, and then pop the other bearing over the axle and tap that one in.
You should get virtually no play on the axle when the bearings are seated correctly (although I have noticed this can vary with Perry SP's).