Easiest way to know the EXACT X/Y's is :
Take a screenshot of your chanarcter WITHOUT equiping the item.
Take a screenshot of your character WITH equiping the item
Open photoshop and open those three images :
1- First screenshot
2- Second screenshot
3- Your item
Now, put them all in one image and line them up like this :
-ITEM
-2ND SS
-1ST SS
Now Drag the item to the same exact place like the second screenshot and delete the screenshot, now you will have like this :
-ITEM
-1ST SS
Now, move up the item wherever you want it to be BUT count with it as pixels, like if you move :
To the right = 1,0
To the left = -1,0
To the top = 0,1
To the bottom = 0,-1
And keep counting, Example : You moved it to the right 5 times and to the top 6 times, its 5,6
Now the last part is add those numbers to the X/Y's , Lets say the X/Y's are 15,30 now they're 20,36
Enjoy~