ive been using my relatives apple ID for my ipad and now my relative has a new apple ID and no longer uses this one .

Your relative needs to use these links to recover that AppleID

and password:

If you forgot your Apple ID - Apple Support

If you forgot your Apple ID password - Apple Support

Then the relative needs to use this link to remove

their AppleID and password from the iPad so you can set the

iPad up with your own AppleID and password:

before sell/give away iDevice: https://support.apple.com/en-us/HT201351

Only other way is if the relative still has the original receipt from Apple

or Apple authorized iPad retailer showing the serial number of the iPad.

She can take that receipt and the iPad to the nearest Apple store where

they may assist her. A Genius Bar reservation is highly recommended

to avoid delay at the store.

Make a Genius Bar Reservation

http://www.apple.com/retail/geniusbar/

If she does not have the receipt and cannot recover her AppleID and

password using the links provided previously, the iPad will remain locked.

There is no workaround for the security features of Activation Lock.