Soldering and Desoldering components.

@kumaran123 really all you are looking at is either hot air rework stations or a soldering iron. As a rule of thumb for me I use an iron for installing components and for removal I like hot air.  I found that hot air guns are big and clumsy when t comes to soldering small package SMD on a board. I used to end up de-soldering components next to it and melting solder on multiple other places. It will require a lot of practice to get good with hot air. This will of course depend on the package size of the components and how dense these components are places. Cellphone boards are usually pretty packed so I would use a soldering iron.; easier to control where the heat goes. Again all of this is personal preference and you have to find whatever will work for you.