I have just started wrestling(in BJJ class) and I cant seem to get away from people when they have a collar tie on me. How can I effectively remove this grip?
Some other options:
If his elbows are floating and not wedging, then come inside his tie and get one of your own. This will negate his.
If he is yanking you around, hook your hand on the outside where is elbow bends and place some pressure.
Palm/slap the inside of his elbow with the opposite side hand, change levels a bit and get an underhook.
As Dogface recommended the Russian 2 on 1, (which is my favorite and the most high percentage IMO), and a variation of his #2 is to get him to straighten his arm a bit or if he does it anyway, peel at hi wrist. Then drive it downward and arm drag it.
Basically look for errors in his control and attack them. Is he wedging or is his arm extended? Is he driving into you or pulling? Is his elbow floating or inside? etc.