You can reuse the bearings if you know they're new. Just clean them well and repack them with bearing grease. I'll get a load of carp for saying this, but I alwys clean mine with distilled water and repack them after blowing the water out. They're soaked in water based coolant when they're ground anyway and that's the way they're cleaned at the manufacturing plant. If you use petroleum based cleaners, you have to get it all out, because if you don't it will significantly diminish the life of your lubricant.I am just about to replace mine....do I need to replace the wheels bearings at the same time or can I put them back in. There were done recently abs missed the rusty backing plate. Do you need any special tools to do this job or are conventional tools okay? Don’t need a press or anything?