I had the same issue with my 6.5 CM sizing die yesterday. At least with mine it didn't just pull right out. Push the tip of the collet sideways and when it starts to move to the side rock it a little bit side to side perpendicular to the initial push direction and maintain the original sideways pressure and it will pop out. Not an intuitive process. SAC really should have instructions posted on their website.SAC Mandrels arrived this afternoon. I however do not know how to remove the 6mm ER11 Collet and replace with the 1/4” ER11 Collet. I searched for a YouTube video but was unsuccessful.
Anybody have specific details on how this is completed?