I have sprayed with wd40 heated up .... but still unable to remove nut and bolt on rear shock bottom bush any ideas please

 

use pb blaster. Let it set for about 20 mins. Heat it up and hit I again with the blaster. It will usually bust free. wd40 is not that good for freeing rusted bolts\]

 

In addition to the good Dr's suggestions of PB Blaster, heat and time, I find it also helps to hit the rusted bolt with a hammer a few times after applying the PB Baster. Supposedly vibrations help oil penetrate further into the rusted threads. Maybe it's just an old wives' tale (or an old mechanics' tale?), or just a way to vent your frustration on the rusted bolt, but there's little harm in trying it. It doesn't require a sledge hammer or heavy swings. Hit just hard enough to send vibrations thru the bolt several times after applying the PB Blaster. Please wear safety glasses & gloves as a precaution for metal shards flying off the bolt or hammer, and take care not to damage the threads at the end of the bolt.