If you want it to become a crossfade, put the cursor on the transition and press "/" on the numeric keypad. If you wish it to become a cut, press CTRL + "/" on the numeric keypad. Or just right-click the transition, choose Transition on the pop-up menu, and choose the desired option there.
If you want to remove the transition completely (which is what I believe you want to do), left click on the purple 'Transition Properties' cross at the right side of the transition you want to remove. When the 'Video Event FX' dialog appears left click the 'Remove Selected Plug-In' button (next to the Plug-In help button). The transition will then have changed to the default 'Crossfade' transition. Now pull the two clips apart.
But won't it reappear if I drag them back together again or maybe place something inbetween the two ?? K
The section after the split will 'remember' the last type of transition used. That will only take effect if you overlap it again, either with the original event or one you've interposed. You didn't specify that you wanted to re-set the transition but, if you do, you'll need to follow earlier advice.
And "/" will remove the transition, turning it back into a crossfade exactly like opening up the transition dialog and clicking on the "remove" button but a whole lot faster.
But I also added "If you wish it to become a cut, press CTRL + "/" on the numeric keypad" which will not only remove the transition but will also remove the crossfade!
And "/" will remove the transition, turning it back into a crossfade
OK, we're just having a slight problem with terminology. You are not considering a crossfade to be a transition, whereas I was. Your short-cuts are very helpful and welcome.