I was completely terrified of changing the tailpiece by myself in case I caused some horrendous damage to my lovely violin, but a friend has suggested it's very do-able?
Can someone advise me? I've looked it up online and listened to his instructions as well but feel a bit nervous in case it goes wrong. What are the likely risks and is there a 'safe' way to do it?
Thanks!

Perfectly do-able, if you're comfortable changing strings. Slacken them off gently, so that you can remove the bridge without clattering the body and so that the soundpost doesn't fall. Similarly, take it slow and steady when setting it back up, increasing the tension across all four strings a little at a time, checking that the bridge is staying in the correct position.

So the bridge needs to come off before I fully release tension on the strings?

Slacken the strings until there's just a little tension, so that it's possible to remove the bridge by hand, then the tailpiece will either be free to come off the end pin, or you might need to slacken a little more.

Similarly, when restringing, fit all four strings to that same tension, then stand the bridge up underneath them.

Thanks so much for your help - I'll give it a go now

Thanks again!
I'm very pleased to report that I changed the tailpiece, added a better fine tuner to the e string and in the process managed to get rid of an irritating little buzzing sound! Fab!