How to undo bolts on Ford Galaxy 2003 Front & Rear brake caliper to renew disc's and pads?

I need to renew the disc's and pads at the front and rear of Ford Galaxy 2003. I have the correct sockets and a large extension bar, but they will not budge (front or rear). I have tried WD40, thinking of trying a little heat, but its a bit near to the brake hoses. All suggestions gratefully received. I have a full workshop manual on this car issued by Ford which just says that they are tightened to 190Nm. The front bolts are huge 27mm and the rear bolts are 18mm.

Are you turning the bolts the right way? The bolts turn left to take them out and right to tighten them! You don, t want to use heat around brake fluid! Put a 6 point socket on the bolt, a 1/2 inch ratchet, and use a cheater pipe if they won, t come loose!

Use a hot air gun or a hair dryer and give them a good heat. The bolts have thread lock on them are usually very tight. Hope this helps

You need a 1/2" metric socket set, 1/2 ratchet and a 1/2 breaker bar.