As @boneyard says, it is generally prudent to contact your F5 Account team to discuss this transition. If you are unfamiliar with F5 products, F5 does offer extensive training, including a number of useful free training courses. You can find information here:
https://f5.com/education/training/free-courses
Also, as @boneyard says, it is imperative that you transfer the contracts to your organization and ensure no gaps in support. Otherwise, you will be unable to open support cases for these devices and you will be unable to upgrade code. In order to effect the transfer, you will need to provide, at a minimum, the list of device serial numbers to your F5 Account team:
https://support.f5.com/kb/en-us/solutions/public/3000/700/sol3782.html
If you are uncertain who the contact for your F5 Account team is, you can use this form:
https://f5.com/products/how-to-buy
or contact F5 Support:
https://f5.com/support