Didn't you get the manuals with the tractor? You should have got one for the tractor and one for the loader.
Mine has a FEL (older Deere 670), but the procedure may differ slightly so I won't explain how I do it...but it is easy! First time is a bit intimidating, though. Re-installing the FEL is a bit more work (mostly getting the tractor aligned to the FEL frame is a bit of trial and error, initially). I'm sure one (or more) of our TBN bretheren will give you a better response then this one.
However, once you've done it a few times, removal takes less time then it did for me to write and post this response.
If you didn't get the manuals, you can at least read the tractor manual online on the Deere website (it'll be slightly different as the new 4100 has changed a little bit from the '98), but that won't help you with the FEL removal. I've not seen loader manuals on the Deere site...can't say I've looked though. Strongly suggest you do order those manual (tractor and FEL) if you don't have them.