If in a hurry just cut the seed head off. You can cut the branch bit of later to make the plant tidy. Hopefully I'll be doing this, this weekend.
I go out in the garden before work to have a quick de-head, then have a general tidy up round the plant when I have time. With all plants you have to fool them in thinking 'I need to flower so I can make seed.'
Once a plant has made enough seeds for its species survival, it wont flower so much. that's why you hear gardeners on TV talking so much about de-heading, so we get more flowers.
Hope that helps. Just ask if you need anymore help