Where the lower control arm bolt goes though and bolts to the nut in side the lower cross member seems to have come lose and moved up to where you can't bolt the control arm back on.

How can I fix this? I was thinking about cutting a hole in the bottom of the cross member to put the nut back in place, I would have to make the hole big enough for a 19mm open end wrench.

Is this is only and best solution with out replacing the cross member?

Any help would be great never had an issue like this with the bolt moving in side the frame and not sure the best way to correct it now as there is no holes in the cross member it self that I can access the nut.