I have changed the sponge on LK150 and Brother 350 by tying a ravel cord to the old sponge and pulling it out and tying the cord to the new one and pulling it through. As long as it is tied very close to the end it is no problem. Ravel cord seems to be strong enough. Just make sure the machine is on such an angle that the needles don't fall out. Take off the end plates and it is no problem. 10 minutes tops.