@saraniimuller The alcohol needs to go under the battery and soak in.
The quality of the alcohol makes a huge difference here, you need pharmacy-grade 70+% isopropyl alcohol and not the dollar store version.
Squirt it around the edges of the battery, tilt the phone every way to leave it a chance to get under and leave it for 5 minutes.
If you have a wide plastic tool like a ruler, that helps to pry the edge of the battery up for the alcohol to get under without causing any pressure points. Pry slightly and squirt more alcohol, wait then pry more. Soaking the end of the tool in alcohol helps with the prying as the adhesive can't re-adhere.