get a bucket, or whatever the critter in it, and spend a few hours replacing like 1/4 of the water every 15min with tank water, then 1/2 the water every 15min. Many even do it with a steady drip useing a little air tube u can buy a valve for it to make it drip slow enough or tie a loose knot in it until the water drips are steady and will add enough water to replace as the above states.
Eventually ull have pretty much 100% tank water in the bucket or at least so much tank water the rest is diluted.
However at this time I also do a dip. With a product to make sure theres no evil bugs or paracites coming along for the ride.
I actually do it over a quarantee period in a tank but you can do dips for 15min during aclimation which is far better than not doing it at all then having ich or something else get into your show tank.
if you want to talk products let me know
jdecter@hotmail.com