Heat is not a bad idea. The secret is having a high power, oxy acetylene or oxy propane concentrated just on the outer joint. In a short sharp burst it won't have a chance to travel to the hub bearing. The trouble begins if you use a hot air gun or plumbing blow torch over a long period. No7 - 2003 V8 Vogue

some photos for inspiration

Still can't get it off

Going to take it to a mate who's a coach mechanic so hopefully have more luck! 

Look like the trick is a big fat cold chisel on the ears of the ball joint, or maybe even your fork splitter  .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Did you try the sharpened cold chisel, that is what worked for a couple of us, but always easier if you can take it somewhere with better facilities?

I haven't yet as I need to at least get the other bolt out first, it I can get that out I don't need to get the arm off the ball joint as they're both getting replaced obviously!

At least I know for the other side that my local Indy can earn some money!! 

Did you try tapping in the next size up torx bit into the bolt ?

I did try, it's so seized up it just rounds instantly.

Can't knock the bolt round with a chisel either

Screwed... 

Yes torx heads on rusty bolts are a stupid idea!!

Sounds like it will need drilling and tapping. Can you get a grinder in to get the head off it then at least you stand a chance of getting the ball joint out. Once that it done then you might get a stud removed on the exposed end, but apart from that and a lot of penetrating fluid I can't see many other options. There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
KIA E-Niro 4+
2021 Discovery 5 D300 MHEV commercial

That's what I was thinking!

My plan was to grind the heat off the bolt then smash the ball joint through and remove the rest of the bolt with some pliers or something!

Trouble is need to take brake disc off, and the calliper bracket won't come off the hub either  

that's why I leave it all to the dealers to sort good luck !

Got to find a garage that will attempt it now guess I'll be cancelling my trip to Germany on the 8th! 

had mine done by beadles

Stacker wrote:

That's what I was thinking!

My plan was to grind the heat off the bolt then smash the ball joint through and remove the rest of the bolt with some pliers or something!

Trouble is need to take brake disc off, and the calliper bracket won't come off the hub either

i think you are still in with a chance if you can get a grinder to the heads of the bolts and grind them back until you reach the lugs, then as you say, remove the ball joint using a a chisel and hammering from the top while supporting the hub which should leave a small amount of thread that you can heat the top of and from underneath and a splash of shock and unlock for good measure and then try mole grips on what is left protruding of the thread as i doubt you will get a stud extractor on it or screw a nut on if there if is any thread that is left and weld it to it. In theory once the head of the bolt is gone it is only the rust that is holding it in.
This may depend on getting that bottom ball joint split for access or getting it to a garage while you can still drive it.
Pic below showing the splitter i used

Click image to enlarge

It's literally either that or garage, but as I said can't even get the brake caliper bracket off!

16mm bolts, started to round with a 12 point socket so got a 6 point but couldn't get enough leverage, windy gun wouldn't even touch it just vibrated forever and ever and it wasn't any looser

Seriously considering selling the car, can't be dealing with this!