Performance power pro drill [ model COD 1050D ]?

Hiya ,
I've managed to melt the chuck grip...
I have a new complete chuck to replace it.

I've looked down the chuck hole with the chuck jaw clamps fully open to their widest setting..Normally there is a screw
to release but there seems to be nothing to release the chuck complete.Can you please help ?
Many thanks.Best regards,
Iain