Basically you don't as the majority are grafted and the ones you can take cuttings from need professional kit to grow the acer.

thanks

I agree with Mg but you might try taking seeds and planting them if it has them, I noticed earlier in the year a little seedling growing, I dug it up and planted in a pot, put it in a sheltered place !! then went on holiday!! needless to say it has gone!! but if I had looked after it I might just have had a small tree by now!! lol you notice I say MIGHT.!!

Doubtful Maggy - the seed will not necessarily produce the same tree as the mother tree. Depends on what it was pollinated by.

Really? this little seedling I found was a miniature of the Acer Aconitifolium I have.