2003 GMC Envoy six cyl.

I am planning on removing the trans from this vechicle and I see there are two rubber plugs in the underside of the bell housing and underneath the plugs there are two what looks to be 10mm bolts. What are these bolts for or what do they hold in place. Should they be removed before I remove the other bolts and separate the trans and engine. Don’t want to bust something right from the get go.