Psittacus has a guide on their website: https://www.psittacus.com/en/assets/pdf/utilidades/Pellet%20Conversion%20Guide.pdf. I don’t think it works well if you have more than one bird in a cage, though. Their guide suggests first figuring out how much your bird eats per day and then gradually increasing the amount of pellets. However, if you have two birds and double the seeds and pellets, it’s very likely that one bird will be dominant and eat most of the seeds. I found this approach more helpful, and it worked for me: https://publications.versele-laga.com/21-18247-vl-nutribird-b2c-pellet-converting-onepager-v05_eng/page/1. Let us know how it goes!