2.0 valve stem seal replacement?

Sorry in advance if someone else has covered this but I couldn't find any info on the subject, I have an 02 Mazda protege5 2.0 and recently it has started burning oil, quite a bit. It always burned a little on start up but stopped not long after so I assume its valve stem seals and now their getting worse.
So what I want to know is there a way to replace them with out taking the head off? I've never replaced valve stem seals on something with dual overhead cams, is there a special valve compressor for this engine?
I was wondering if it would just be easier to remove the head and do it that way? Any information would be greatly appreciated.

I've heard there is a way to do it without taking the head but need special tool specifically for this, there is alot of info to be found i need to replace mine too. if i find some good info i'll reply.

The shops can use compressed air forced into the spark plug hole to hold the valves in place when the seals are replaced,... But I've heard of a backwoods approach where you remove the sparkplug and feed a good length of rope into the hole with the cylinder at BDC (with a couple of feet left hanging out so you can pull the rope out when you're done) then slowly turn the crankshaft a bit to compress the rope gently to push up on the valves in that cylinder to hold them in place.

Personally I'd give it a try,... I've never done it but if it doesn't work then you just take off the head to get the valve out if it falls in. If it works it could save a lot of time, labor and money,... even if just the cost of a new head gasket.