Bushes in general are fairly easy to remove, but a total pain to get back in. They are press fit, so you'll need a good solid vice (preferably large) vice to act like a press.
If you've not got a vice, buy a new wishbone (from the bay). It's more expensive than changing just a bush, but it's much much easier. Also unless they are fairly new, replace the balljoints whilst the bottom arms are off.
(And if your wishbones are not in a sh!tty state you can tidy them up and press new bushes in at your leisure)