Is it painful to get a ganglion cyst removed?

Ganglion cyst: No, it's done under local anesthesia.

Minimal pain: Arthroscopic-assisted ganglion excision is a minimally invasive surgical technique and relatively painless, typically performed under general anesthesia. Through small portals, the ganglion stalk can be visualized and excised with precision instrumentation. The cyst can then be decompressed through an accessory portal. Local anesthesia is placed over the portal sites.