Glitch has the right idea for the normal do it your selfer.The vise methoud works just fine. Get all that you need set up first, then heat the old basket with a propane torch. Make sure you are going arround the alloy not the gear it's self. Idea here is to swell the old basket, then a light squirt of oil like wd-40 between the basket and gear.
Using gloves put the works in your vise so the gear is being pressed into the inside of your spacer. Insert gear same way , heat the new basket, small dab of locktite (red) press gear in and assemble.