where do u live? my local will do em for 130 quid (stoke area)
It can be done without removing the tyres, but the hassle isnt worth it really. You'll spend ages masking it off and if you get any on the tyres its a pain in the ass.
Firstly prep the alloys accordingly (fill any dents etc) and give em a good key with some sandpaper (whatever grade you feel necessary, as it depends on condition of alloy) Then you need to use a good solid primer (i find the halfords filler primer to be quite good), and one a solid coat is applied flat it down. The spray with the colour of your choice. I generally start with a think coat, and try to put a thick coat down towards the end (if i'm feeling brave) as this gives the best finish. However if your not overly confident dont try this, and if you do make sure the conditions are warm and dry or you'll have problems. If you get any runs, dont worry, just leave it over night and use some find snadpaper (1200 grit ideally) to flat it down. Once this is complete its time for laquer. Because these are wheels and will take a fair amount of abuse, u'll need quite a few coats. Again as with the colour start with a dusting, then if u're confident, go with a thick coat as this will give u the best finish. If its not a warm day, have a hairdryer handy and this will help to stop the laquer going cloudy. Leave at least a couple of days before fitting as this is generally how long it takes for the laquer to cure. Then, before fitting, u can polish them, to get a flatter finish, and give a few coats of wax and sealent to protect the wheels further.