depends...on you. on how adept you are with mechanical work. its not easy. takes a while, and u need to be very careful. also need a special crank tool. ask honhon about it, hes done them. there is alos a write-up on the site too, with a ton of pics.
i usually have a shop do my work, so that if i have an issue, i can make them fix it. its all about liability and accountability for me. but not everyone can do that.
stage1's you can run without a tune... stage 2's i would highly recommend a tune.
stage 1's im sure i can do in my sleep, because they dont require valve springs to be replaced.....
stage 2's and above require valve springs to be replaced, so thats another 200$ roughly for the valve springs and retainers... the valve spring replacement isnt really hard, just time consuming... im sure now that after ive done it... i can probably replace the cams within about an hour or alittle longer... its not really that hard... but as long as you are prepared and alittle more prepared than that, you'll be ok...
remember, there are little odds and ends you'll need to do the full swap and such...
heres the list of stuff i had when i did my cam install:
stage 2 crane cams
crane valve springs with titanium retainers
CFM cam alingment tool
Summit Racing AIR HOLD(holds pressurized air in cylinder so the valves dont drop in)
two FL910 motorcraft filters
5quarts of 15w40 rotella T oil(used with the first 45mins of running)
5quarts of valvoline 5w30 oil
1 bottl of crane cam break in additive(used also in the first 45mins of running)
extra tubes of assembly lube from crane
bluepoint(snapon) OHV spring compressor.
when i start to work on my 2.3L head this winter, ill go a head and post a step by step on how to do the valve springs and cams and such, sinse its all done on the top of the head...
I have the Cosworth stage 1 cams(Part # FSYD0222 & FSYD0173) and really love them. I didn't notice any difference down low but after 4k rpms you can tell a pretty good difference. They also have no problem with a stock idle but sound pretty mean with a 900rpm idle.