Hi Kaleem

In regards to the frozen shoulder, the shoulder may be in the freezing or frozen stage. In these stages i do not recommend mobilisations as they do not seem to help and only cause more pain and may even flare up the problem.

In general you may try soft tissue release and some heat therapy prior to mobilsations. This allows the joint to free up meaning the glides may become easier and easier for the patient to tolerate. I have some friends who us IF/TENS for 10 minutes prior to mobilisations.
Also when the patient complains of pain when mobilising, try altering the direction of your force and ask the patient how that feels.

good luck