plus make sure that high torque fastners (spindle and headstock top nut) are slackened with the bike on the ground.... it's an easy way to bring the lot crashing down!!!!
once the bike is up in the air double check it is secure and stable.... a good friend of mine spent about four hours trapped under his own bike in his garage after it fell off a stand during repair work .... luckily his missus popped out to let him know his dinner was ready and got the neighbours to help extricate him!! how we laughed!!!! but it could've been more serious if it had ended up across his chest!
good luck with the swap and putting the bearing races that go into the frame in the freezer for half an hour before fitting will aid the process no end!!!