Glass Sliding Door Roller Assembly

Unfortunately, there isn't any markings, numbers or any other symbol on the roller assembly or the door itself. I need just 1 set (2 wheels total) Not sure if I'll need the whole assembly, or just the part with the wheel attached. I bought just the wheel at Lowe's to see if I could just replace it, but can't figure out how to remove the pins from the old wheels. I really hope you can help me find the right piece(s), or direct me to where I can. Thank you.