If you mean whole coffee beans then do this:
Pound the roasted beans into a fine powder, or as fine as you can get them.
Put two tablespoons of the pulverized coffee into a coffee filter and put the filter over a clean cup.
Pour boiling water into the filter until the cup is filled up. Let the filter soak into the coffee water and steep the ground up coffee.
Let it steep for a full five minutes.
Discard filter and grounds, drink coffee.
If you mean you already have ground coffee but no machine to make it in, you can use exactly the same method without first pulverizing the coffee beans. In fact, there are French coffee presses--available for little money and almost everywhere--that make coffee exactly in the same way. You put the coffee into the pot, pour boiling water over it, steep it for five minutes, then push down on the plunger to contain the coffee grounds, and drink your coffee. If you can't get a French press, you can assemble the coffee and the water in any container and then strain it before you drink it.