I concur with Nick. The crown race seat should have been machined by the fork manufacturer. If it is not seated properly, the headest will eventually loosen and you'll damage the bearing surfaces through Brinelling. Unless you have a proper driver for installation you can damage the crown race seat itself.
However, the drivers are simply enough to make. All you need is length of heavy lead or brass pipe that is just large enough to slip over the steerer column, but not the top edge of the crown race. You could use steel pipe, but a material softer than the crown race is preferred to avoid damaging the crown race. The end of the driver used to set the crown race MUST be cut square. Mark the square cut end so that you always use the proper end for seating the crown race.
When installing the crown race, ensure the fork is supported under the crown. The crown race can be seated by hand if the driver is heavy enough, or it can be done using a hammer, if the driver is longer than the steerer column.
One last item of caution. There are several diameters of crown race and crown race seats. To work properly, the crown race should be an interference fit of 0.1 - 0.2 mm (i.e. the inner diameter of the crown race should be 0.1 - 0.2 mm smaller than the diameter of the crown seat). If the crown race is too small for the crown seat, it can split when being driven and/or you will damage the crown seat. Too big and you'll have a loose heaset that you cannot tighten and will wear out quickly.
IF YOU ARE IN DOUBT OF ANYTHING, TAKE IT TO YOUR LBS!!! IF THEY SCREW UP, IT COMES OUT OF THEIR POCKET, NOT YOURS.