header tank.

My trusty c220cdi auto has over 280,0000 on the clock so I shouldn't be too surpised or grumble that the header tank has sprung a leak and needs replacing. Any suggestions as to the hose clip and pliers type I'll need to wrangle it off?

The Expansion tank on the slk 230 T reg exploded when the car overheated. I've sent off for a replacement expansion tank but the one that has been sent to me from the supplier doesn't have a white ball attached (for want of a word) Can I fit it and will it work okay? Also once I have refitted...