Step 1: Choose a hideout, best if in a very rural area, with no nearby cities or large communities.
Step 2: Call my dad and tell him to bring me some weaponry (my dad's really good with these kinds of things). Weapons of choice: samurai sword and any powerful semi-automatic firearm.
Step 3: Find a large vehicle, preferably a UPS truck, or maybe an RV, anything that can carry alot of passengers, and hotwire it if need be.
Step 4: Round up all the family members and friends I can think of, and take them to hideout mentioned in step 1.
Step 5: Arm the more powerful family members of the family with high power weapons and tell them to guard every opening of the hideout that the undead could possibly get through.
Step 6: Return to town and stock up on canned foods and water, anything edible that wont expire quickly, and return them to the hideout.
Step 7: If possible, inform the military of the invasion of the undead.
Step 8: Stock up on weaponry, anything from firearms to power tools, and ammunition. Grab anything that can blow some brains out or shatter a skull, or sever a head.
Step 9: Encourage surviving town members to fight back against the invasion of the undead.
Step 10: Fight off the undead the best you can, and wait for military assistance. If you couldn't get any military assistance, then you may be in trouble, especially if the invasion is widespread. Keep fighting and try to wait it out. It should be easier to wait out if it is not widespread.
Step 11: Dont stop fighting unless your killed!