How to get an Xpath of element which is changed its class or something when mouse is over

Miscellaneous
1

I want to get an Xpath of a element but its class or something that related to Xpath is changed when mouse over.

How can I get a exact Xpath?

I use Spy Web, Chorme&IE Developer mode

but cannot get it sometimes.

2

How about using ‘Xpath Helper’ add-on from Chrome? https://www.youtube.com/watch?v=3mR9qyeJ9uo