Create a transition from a source state by moving the cursor on the state, right clicking, and then selecting new transition from the menu. Move the cursor to the target state of the transition and left click. A multi-segment line can be created by left clicking at intermediate points. Right click at any time to cancel the transition.
Before the transition is complete a dialog will pop up. Select whether you want it to be unconditional, conditional upon an input, or an "else" (taken when all other transitions out of the source state are not taken). For conditional transitions, type in an input signal name (which will become an input to the state machine), the number of bits, and the value that enables the transition. Click on ok to finish the transition or cancel to cancel the transition.
To remove a transition, move the cursor over any part of it (it will turn pink) and right click. Answer yes to the dialog if you want to remove it, no if you've changed your mind.
Remove all transitions from a state by moving the cursor over the state, right clicking, and selecting remove all transitions.
Move a corner of a segmented transition line by putting the cursor on a corner, press and hold the left mouse button, drag the corner to its new location and release the mouse button.
To change a transition, delete it and then add a new one.