I'm not going to pretend that this is the only way to prevent your EGR from operating. There are a few other methods and I'll explain them below.
1. Metal blank plates
These can be bought from places like ebay for a few pounds. They literally go between two of the pipes and physically stop the exhaust gas from going back in to the engine. However, there are a couple of problems with this. The first is that you have to remove various parts and be mechanically minded enough to fit the plates. It's not a huge task but if you've never held a spanner before and aren't sure what to do then you would be put off buying them. The second issue is that the ECU has no idea what you've done and still tells the EGR valve to open. The ECU can then get confused when it expects to detect exhaust gas in the engine but there is nothing there and under certain circumstances you'll get the orange engine warning light on the dash. These plates are fine for the older 'classic' shape Mitsubishi L200 as the EGR works differently but they can cause issues with the 'New Shape' 2006+ models.
2. ECU Remap
The other option you have is to take your truck to a specialist and have an ECU remap done. Make sure that you are getting the EGR delete map as well as some places will just re-map the engine for more performance or economy but leave the EGR alone. The issue with this method is that you have no way of easily restoring the ECU to normal should you want to. My prevent modules can be taken off in seconds and it will instantly restore the truck to normal operation. Remaps also cost significantly more than these modules!
*** - Don't worry if you have an external performance chip (the ones you actually plug in). My modules will work perfectly fine with all the major brands of performance chip.