You'll have to add a Nutsert (threaded insert that is "swedged" into a hole in thin material) because the swingarm isn't thick enough to tap threads into. Second option is to have threaded bosses welded to tha swingarm.
Already did this to my M620. I own my own Thread-Setter kit from Marson. Heres a link to their site so everyone who isnt familiar with the product knows what they are and how they work. Theres even a picture