Small crts like that aren't bad. Just make sure you got a place for it first - get some old towels and make a 'bed' in a safe place for it. Remove the plug in the back and focus/and deflection coils, then loosen the support strap up front (hold the tube so it doesn't fall out), and carefully lift the band out of the way and slide the tube out the front. Just don't bang it into things or drop it, and don't hold it by the neck.
I much prefer working on a chassis without the tube in it.
Oh yeah, ground the hole where the HV lead plugs in, even if the set's been off a while. Some tubes like to store up a surprise over time anyway (not dangerous, but could startle you into dropping the tube).
Once the tube's safely out, I like to clean it nicely, to get all that dust and junk off. Just don't removbe the dag coating
