You will be prompted to continue download, Click on Continue
Open DiskMaker X by pressing
Command ⌘ and space
Click on Yosemite(10.10)
We already downloaded OS X Yosemite, So click on Use this copy
Click on Another kind of disk
Make sure you choose right USB/HDD (Will be formated)
Make sure you selected right USB/HDD
Next step provide administrator password, click on Continue
Provide administrator password and click on OK
The installation may take a little time, so grab a cup of coffee and relax.
Alt/Optionkey on your keyboard as soon as you hear the Mac’s startup chime.