Q.Soil Sample Testing
How do I prepare and where do I bring in a soil sample fo testing? When can I bring in a sample? What is the lead time for testing? What costs are associated with this service? What exactly is tested – are pests tested as well? I believe I have nematodes and want the soil tested for that before I dig up the plant.

Certified GKH Gardening Expert
A soil test is not for pests, but for nutrients and soil pH. You can pull up the plant and examine the roots for nematodes. Your local extension office can help with a soil test and what to do about nematodes. These articles will help:
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/are-all-nematodes-bad.htm
https://www.gardeningknowhow.com/garden-how-to/info/what-is-extension-service.htm