Originally Posted by: jackyjoy826

have you (or someone you know) put a tremolo bar[br]on a Les Paul . . .[/quote]

I have not, but I've known a few guitarist that have.

Originally Posted by: jackyjoy826is it risky if i gave my guitar to a guitar shop to put a bar, is there a chance they might do something wrong and destroy the body?

It depends on which model you have installed. Yes, some of the models require more detailed work than others. You definitely want to know the guitar shop you are considering knows what they are doing.

[quote=jackyjoy826] I am thinking to put a bar like Neil Young's do you know what it is?

That's a Bigsby B-type.

https://www.stewmac.com/parts-and-hardware/bridges-and-tailpieces/bridges-and-tailpieces-for-electric-guitar/bigsby-vibrato-tailpieces/bigsby-b7-vibrato.html

There are several Bigbsy type vibrato assemblies. There are many YouTube videos on the topic.

https://www.youtube.com/watch?v=-42G8P7niZs

https://www.youtube.com/watch?v=GWyGMfb243Q

There are other options available.

https://stetsbar.myshopify.com/

Hope that helps!