To "explode" a group, use the AutoCAD command: UNGROUP
Of course "exploding" a group may not be the best choice for every situation. In groups, if you just want to grip edit something within the group, set the system variable GROUPDISPLAYMODE to 0. This setting will display grips on all objects in the selected group. It will preserve the group while allowing you access to grips to make changes to individual objects within the group.
Here are a few images to show the difference between the three settings available in the GROUPDISPLAYMODE system variable. Each image shows a group consisting of an mtext object and a rectangular wipeout that has been selected within a drawing.
|GROUPDISPLAYMODE set to 0|
|GROUPDISPLAYMODE set to 1|
|GROUPDISPLAYMODE set to 2|