Rear window Runners RUSTING

I have a freelander on a 05 plate.
There are signs of the rear window runners rusting at the bottom.
Classic signs are that the rubber is bubbling.
Is this an easy fix or will it cost me the earth?
Can these be Repaired or do they need to be replaced?
If you have been through this please can you help me with a solution.
Regards

Arrow

My 52 plate is doing the same thing, i think it will be more hassle than its worth to get them fixed, let it develop!

Thanks i will consider it

Is that what the lumps are on my front n/s door.

I also hve on the seperator/runner on the passenger doors. Are these easy to replace, doesn't look good

Im having them looked at this week. I will post my findings later