Chrisp

I tried to change the fan to the same one you put, but I faced with two problems. One is the connector, the new fans have 4pin connector and sonnet echo has 2pin fan chip. Do I have to cut the original fan wire and solder them to new one to replace the connector? Second problem is that the 25mm fans are too big to fit in. After I set the fan on the chassis, I could not put the body in. Could you please give me some brilliant insight?