BF15D old corroded anode won't come out for replacement

[Smiffffy]

One of my old partially corroded anodes won't come out. Does anyone have any ideas to get it out please

 

[ahicks]

Picture might help?

 

[MattFL]

Why won't it come out, are the screws stuck?

 

[Smiffffy]

Picture might help?

I've managed to get the nut / bolt out but the remains of the anode are still in there

 

[Smiffffy]

Why won't it come out, are the screws stuck?

Bolt is out and one side scrapped out as it was powdery the other side is still metal and seems to be corroded in. I've tried hitting it with a hammer and screw driver from several angles.