Without knowing the specifics (how many years of experience, what kind of industry connects & their worth, current split between founders and other stake holders etc), it is difficult to estimate the equity share.

Depending on the above, a share anywhere between 10-20% should be good enough. This again varies with the monetary compensation the CPO is provided.

If one wishes to do it themselves, Youtube or www.ifixit.com can help.

If not, then just call for a technician from the manufacturer of the printer.

The credits that you already received are under AWS Activate Founders. Quoting from the AWS website, "If you have previously received AWS Activate Founders benefits, you are ineligible to apply again. You can only receive AWS Activate Founders benefits once."

However, check if you are eligible for their AWS Activate Portfolio Program.
https://aws.amazon.com/activate/portfolio/
This provides $100,000 USD in AWS Credits.