Yes, it's pretty easy
I have the 488 mkII, but it looks like it should be fairly similar. Here's the idea: The recorder can only do up to 4 tracks at a time. Therefore tracks are grouped into 4 groups. Tracks 1&5 = group 1, tracks 2&6=group 2, etc. So you can only record on one track from each group, i.e. you can't record on tracks 1 & 5 simultaneously, they're like "radio buttons", "either,..or".
Remember, that in recording mode tracks refer to tracks on tape, not the strips on the mixer, think of your mixer section as an outboard mixer, it has nothing to do with track numbers. Your first 2 strips of the mixer have preamps. To assign any one of them, or, in fact, any strip to a certain track do this:
Track 1 2 3 4 5 6 7 8
Pan L R L R L R L R
G 1 2 3 4 1 2 3 4
R 1 2 3 4 5 6 7 8
"G" means "Group assign switch", it's either 1L/2R(for tracks 1, 2, 5, 6) or 3/4 (for tracks 3, 4, 7, 8)
"R" means recording track, there's buttons in recording section that specify which track is being recorded. There's only 4 unique combinations of the "Pan" and "G" controls for the 4 groups. The "R" selects whether you're recording to track 1 or 5, 2 or 6, etc. Note, that you can't assign "R" to 1 & 5 simult. These "G" and "R" are my abreviations, cuz I don't remember what they're called, but you should figure it out. It's easier than it seems. Of course downloading a manual will make it even easier. Hope I helped and not confused