First prepare your jars using a water bath:
1) wash and rinse well any jars you are using.
2) Put a pot of water on to boil. The pot should be deep enough to cover the covered jars with at least 1 inch of water.
3) Place an inverted plate in the bottle of the pot (this will keep the jars off the bottom to help prevent breakage. Make sure it is an old plate in case it gets damaged)
4) when the water comes to a boil, using tongs place the jars, lids and lid inserts into the water (you might have to do 2 batches)
5) Boil for at least 5 minutes, preferably 10 minutes.
6) Carefully remove jars and lids using tongs. Invert onto a clean tea towel.
7) while they are still warm, turn them over to fill.
8) fill with BBQ sauce leaving 1/2 inch min. at top
9)Put inserts and lids on jars. Do not over tighten lids
10. Place jars in water bath and boil for 10 minutes.
11) Remove jars and leave them undisturbed for 12 hours.
You should hear the lids "pop" at some pint. This means they are sealed. Press on the centre of the lid. If it doesn't move, then they are sealed properly. If you can press down on the lid. tighten them and put pback ion the water bath. If it still doesn't seal, check the insert for any damage or scrapes,