Ansible 2.5.3 to Ansible 2.9.9 upgrade steps and dependancies

Hello All,
I have ansible 2.5.3 and Python 2.7.5 , I need to upgrade Ansible to 2.9.9.
Can someone please guide me on what the dependant packages or Python libraries I should upgrade while upgrading to Ansible 2.9.9.

Thanks
Manohar