Help - Handbrake ineffective

[baby_father]

Can anyone either provide instructions or point me to somewhere where I can work out how to fix my problem.

The car was parked up for 5 months waiting for an insurance claim to go through after it was hit by a lorry (damage was mainly superficial).
However. The handbrake was left on during this period (not of my doing) and as a result it siezed shut.

I have freed it up so that the car can be driven, but the handbrake doesn't work well enough to pass the relevant UK roadworthiness test that you need to drive it on the road.

A friend told me that it is the calipers that either need freeing up or replacing. i am reluctant to just PAY someone to replace them as I want to know how to do as much of this sort of thing myself so that I can both save money and that any unscrupulous mechanic is not as likely to rip me off.

Is it a simple case of putting some WD40 (lubricant) in a strategic location, or should I take it to a 'Professional'?

Thanks in advance!