For ease here is the procedure for a G1000
1) Insert the SD card containing the flight plan in the top card slot on the MFD.
2) Press the FPL Key on the Control Unit to display the Active Flight Plan Page on the MFD.
3) Turn the small FMS Knob to select the Flight Plan Catalog Page.
4) Press the FMS Knob to activate the cursor.
5) Turn either FMS Knob to highlight an empty or existing flight plan.
6) Press the IMPORT Softkey.
If an empty flight plan is selected, a list of the available flight plans on the SD card will be displayed.
If an existing flight plan is selected, an ‘Overwrite existing flight plan? OK or CANCEL’ prompt is displayed. Press the ENT Key to choose to overwrite the selected flight plan and see a list of the available flight plans on the SD card. If overwriting the existing flight plan is not desired, select ‘CANCEL’ using the FMS Knob, press the ENT Key, select another existing or empty flight plan, and again press the IMPORT Softkey.
7) Turn the small FMS Knob to highlight the desired flight plan for importing.
Press the ENT Key.
I guess it would work the same on a 430.
It would save time and effort with a complex route involving a number of GPS coordinates which are a pain to process while waiting to be "despatched".
I tend to keep my routes in consequence a great deal more simply - usually a straight line if at all possible.