How to Downgrade Windows 8 to win 7 IN lenovo ideapad y510p

helo i bought a laptop idea pad y510p .. but how to install windows 7 on it

i tried using legacy mode to boot win7 bootable pendrive ,but after reached to advance partion option in win 7 setup . it says it cant be install on gpt partition .

heros help // win 8 is disgusting boring OS in world . even no start buttons . it is only for moms and child to learn computer .

and even let me know if i change it wot win 7 then ,is their any issues will happen with display resolution and graphics card . will run and support properly .?