It's hard to tell, possibly, possibly and probably not.
You need a new wheelset -you'll probably have to relace the existing rear hub (you probably won't be able to get a wheelset with the freewheel hub new now) to keep the original shifters -that's not cheap in itself unless you do it yourself, plus you say you need new tyres. What about the front derailleur? Is is the right size? The bb width? What about the headset? Do the brakes fit? (can't remember if the LHT only offers canti post studs). What about the seatpost diameter? BB cable guide? New cables? (all the little things add up).
Another thing to consider, from your post, it sounds like you don't have all the tools necessary; add on some money for those, and again, these tools add up. All things being said, unless you're in love with those bike parts, and unless you really want to invest money in tools knowing you're going to be using them enough in the future, I think you'd be better off trying to buy a built up LHT or used equivalent (certainly so as I'm assuming your current drivechain has some wear associated with it?).
The good news is that if you are mechanically inclined, I think you could do all the work yourself. But: though you might be able to scrape in below the $900 cost of a new built up LHT -probably less than a couple of hundred dollars, maybe less than $100 total savings depending on which new components you still need to buy -I think it might be a penny wise but pound foolish solution.
edit: I assumed the Schwinn Woodlands had a freewheel -when the poster said they got it when they were a teenager, I assumed quite some years ago!
Last edited by Nigeyy; 04-14-08 at 11:00 AM.