If no welder, pick the closes size backwards drill bit and cross your fingers. If one choice for welder get a small mig welder and use .030 70s solid mig wire with welding gas, great for stuff like this, great for tack welding things together, great for filling in holes, great for thin sheet metal, great for vertical down, great for beginners............. I have a 7 year old Millermatic-211 with Auto-Set, this is the newer style. I'm sure Everlast makes good mig welder's to or Lincoln, HF maybe not so much
Miller Millermatic 211 MIG Welder with Advanced Auto-Set (97614) 715959598545 | eBay
Miller Millermatic 211 MIG Welder with Advanced Auto-Set (97614) 715959598545 | eBay