Can extractors be changed without taking out the engine?

Yep 

just remember through use lots of rust anti seize spary and be prepared for broken studs and such because it can happen and will or may. When mine was installed on the white mr2 lots of studs broke and took them two hours to do and such they had alot of fun with it the exhaust shop. So don't expect it to be done in an hour or less look much towards 2 and beyond that way if it takes less and no studs break then well consider your self lucky. Good luck stick up photos of before and after want to see :)

Haha been a little bit dead noticed that. Well if your doing brakes just make sure everything is tight and that after you done PUMP THE PEDAL to many people forget and have no brakes until they have pumped the pedal a few times in panic on the road.(speaking from experience as well). So please pump them before going for a drive and don't spill brake fluid on paint you will know about it the hard way AND!!!! use lock tight on the brake bolts just for reassurance not necessary but hey stops bolts from unloosen and losing a brake caliper or two is not good while driving.

Buying spares now hey I should start doing that as well hoping to get a second hand motor for her soon as well as a gearbox. Cause if you drive anything like me you **** **** quick. There's a reason why shes been off the road and its due to abuse. Poor MR2 what can I say she handles like a race car might as well treat her like one :D. Also need any help you can hit me up and some other mechanical minded guys on here I'm pretty sure we can give you some insight into things I hope if not then maybe at least point you in the right direction.

Haha no worries. I would look more at the heat rating of it given that brakes get hot. Oh I see hunting down the rare stuff that brakes and such? I'm confident she is reliable enough but foot to the floor and such its really only a matter of time till she goes you can make the time longer by servicing regularly replacing stuff that is giving out and generally make sure everything is good but engines need rebuilds, brakes will need replacing, suspension components will need replacing due to the fact that it all has a limit.

I don't know if that's a good idea given that the exhaust side faces to the cabin and may set the firewall sheathing on fire or the whole car.

Bro, all natty.

It's okay guys I think Mr TDB here just wanted some friends to talk to because he has been rejected all his life, ergo "ya feels me"