I’m sorry that your tophi have reached the stage where an operation is necessary.
Removal is a fairly standard procedure, and is normally successful. My experience from friends tells me that the sooner it is done, the better, because tophi that have broken through the skin can become infected.
As with any surgery, their is a risk that anesthetics can trigger a gout attack. I’m not an expert in this field, but I believe treatment with alkalizing medication before the operation can reduce the risk of this.
Post operation, your priority should be lowering uric acid levels to below 6mg/dL to help dissolve any remaining tophi, and stop more forming.
I know you have also asked about uric acid reducing foods, and I will address that in the gout diet forum. Please be aware that, at this advanced stage of gout, diet will not be sufficient to lower uric acid enough to prevent further tophi build up.
You must get medication for this - traditionally allopurinol, but there are alternatives, with new uric acid lowering drugs slowly becoming available.