Can I remove the joint sponsor after filing AOS (but before approval)?

[KateIdewo 5]

My fiancé’s petition for a K1 visa has been approved and we are currently waiting to schedule the interview. We estimate he will have his visa in the next 3 months. Because I have been staying with him in his home country on a tourist visa, I am currently unemployed (and have been for the past year) and we are therefore using my father as a joint sponsor for the K1 visa application. It is unlikely I will personally meet the income requirements before he comes to the US and we file the AOS, so we plan to use my father as a joint sponsor for that application as well.  However, it is very likely I will have a steady job and exceed the income requirements within six months of my fiancé coming to the US, before his green card is approved. I have a high earning potential and it will not be difficult for me to find a well-paying, secure job once I start applying, though the onboarding process usually takes several months in my field. 

If I have a steady job and meet the income requirements before his green card is approved, can we amend the AOS application to remove my father as the joint sponsor, making me the sole sponsor? How would I do this? I do have about 70k in investments if that would improve the chance of success. 
 

Note: Before anyone asks, the reason I am waiting to start working is because I am 6 months pregnant, so I plan to join the workforce a few months after our son is born because it is unlikely I would get maternity leave shortly after starting a job. My fiancé is expected to have his visa and arrive in the US shortly before our son is due. Although I could wait for him to come until I have a steady job, it would mean him missing the birth of his first child. 

[Boiler 45,733]

You will need a job for some time, generate pay stubs so it is potentially possible, depends how quick you are to file to adjust and they are in adjusting the case. A lot of cases are processed without an interview so possible but no guarantee.

Edited January 14 by Boiler

[powerpuff 6,744]

*** Topic moved from K1 forum to AOS K1 forum as this is an AOS related question ***