iFixit has always been one of our favorite sites for tearing down devices. The site has traditionally focused mostly on Apple products, but now the company has added an Android hub with over 250 guides.
The company rightly states that creating repair guides for Android is a tougher challenge, due to the sheer number of devices that exist. iFixit says there are over 20,000 different distinct devices to cover, so the 252 guides isn't huge. But it is a good start. You can also sign up to contribute a guide if you think you're up for it.
Project Android | iFixit