How to properly extend a lease for another 6 months??

[Steve S.]

My tenant's year long lease is coming due and they would like to extend for another 6 months.  In doing so, the price will go up a little bit and the end date will, of course, be changed.

Can this be done with a 1 page word document i type up stipulating that all terms of the previously signed lease are in effect with the end date being x/x/xx and the new monthly rent being $x,xxx.00?