[Jazzlovessyrians]

This is what I did, other people may have other methods. You can put a towel down in a bathtub and make sure the plug is in (or just use a playpen if you have one) and then put a hideout in there. Then get the hamster out of the cage, I use a big tunnel (a cardboard tube from the inside of a roll of carpet) and put a treat in so the hamster climbs inside then just gently lift the tunnel out and take the hamster to the bath/playpen. Sit in the bath/playpen with them and give them treats to get used to your scent.
Also ruffle the bedding with your hands so your scent transfers onto the bedding. You can also talk gently to them while sitting near the cage and when putting a hand in to feed them if they're not yet comfortable to get in the tunnel to come out of the cage. Hope that helps!