Somebody correct me if I'm wrong here, but I think solfeg is the whole Do-Re-Mi-Fa..... etc. thing. If it is, here's how I can help you.
What (I think) solfeg is, is to be able to have a name/or be able to sing this name for the note based on what interval of the scale it is. Let's work in C major, cuz it's easy.
C (1st) = Doe (A deer, a female deer right? ok enough of that...)
D (2nd) = Ray
E (3rd) = Me
F (4th) = Fa
G (5th) = So
A (6th )= La
B (7th) = Tee
C (1st or 8th) = Doe
They aren't spelled like that, but that's basically how you pronounce them.
So you use them by taking what interval of the scale it is, let's say the 3rd, or E in this case, and you say the name for it (Me).
Practice it in all keys! (ex.. Key of D: D=Doe, E=Ray, F#=Me, etc....)
The reason it is useful is because once you know how it sounds in your head, you can immediately put a melody down in any key, just transfer the Doe, or Me intervals.... etc...
Hope this has helped! Just reply if you're still confused.
There are only two important things in life - There's music and theres girls, not necessarily in that order....
The Ace's Guitar Tricks
The Ace's Guitar Tricks