Before you go tear it apart its best to check the charge port it could be full of lint or other debris. You can sometimes clear it just with compressed air but if the debris is packed in tight it may require you to clear it with a pic. use a plastic or wooden pick not metal as metal can damage the outlet . Dont pry on the center as it can be broke off with enough force and then you would be in a bigger issue.
There could also be bigger issues such as a bad battery , or a bad charge port
This might help [guide|102246]