you need a 14mm spanner for the nut at the back of the sub frame close to the steering rack boot. Then you need 11mm socket and spanner to undo the nuts and bolts behind the radiator on the sub frame pillor. You may need to take the radiator off make like allot easier
Firstly you should never use metric tools on imperial nuts bolts, you will end up damaging something.
ALWAYS use the correct tool for the job.
I don't know what arm your try to remove/replace but I’ve never had to remove the rad to get the bottom one out.
looked in Haynes manual but that wasn’t any help could someone help me
It is in there under suspension and steering 10.7 no.6
And it couldn't be simpler Jack up the front of the car and support on stands, and then remove the road wheel.
Remove the retaining nut and separate the swivel hub ball joint from the lower suspension arm, using a suitable joint separator tool. Remove the through-bolt and nut securing the tie-rod to the lower arm.
At the lower arm pivot shaft, remove the nut and washer from the rear end of the shaft, and then tap the shaft forwards to release the arm. Remove the arm mounting brushes.
Installation is a simple reversal of the above procedure.
Ensure that the flat on the head on the pivot shaft locates correctly with the tab at the mounting hole.
The pivot shaft nut should not be fully tightened until the suspension is supporting the weight of the car, to prevent pre-tensioning of the rubber bushes. Tighten the pivot shaft nut to 45Nm (33 lb ft) and the blower ball joint to 54Nm (40lb ft)