Morris Minor Owners Club

Just started to crack on with finishing the right through brake replacement, have hit a bit of a glitch.
As well as new copper pipes replacing the flexipipes too (as its reasonable to assume they are siezed to the front cylinders), but the existing ones are very badly seized on.
The rear one has snapped the angled bracket with a hole in with no signs of budging at all, the fronts simply wont move either side.
As a mater of damage limitation is the best way to cut them through with a 4" grinder where they sanwdich the bracket? or is cutting the pipe either side of the bracket and ripping it off and replacing the bracket going to be the best way?
Dont want to cause any dame i cant fix without having to wait until next week for parts so any tips would be great.

Apply heat - and release oil, repeat as necessary.

too late
put new brackets on tomorrow, realistically no amount of heat or penetrant was going to shift them. The drivers side one would not move from the cylinder even so little hope at the bracket, had to cut the pipe and smash the pressing end at the cylinder down with a hammer to get a socket on to undo the top cylinder retaining bolt.
Oh well wont need doing again for some years

Oh if you had them red hot - they would have come off!