I shoot USPSA and no matter how hard I work on trigger control, my gun continues to shoots a little low and to the left so I want to get a trigger job done. I'm a medical student so $$$ is an issue. I'm leaning towards Springer Precision and can buy the kit for $130 or send it to them and have Springer do it for $185 plus a lot for shipping. This is my first gun and was wondering if I should just send it in or if I should try to do it myself. I have the AGI video for Disassembly and Reassembly of the XD and have also seen a few youtube videos so I think I can do it (i'd atleast like to think I can

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Also I have a few questions on a few other upgrades.
Why upgrade to a polished striker?
Why get the Titanium Striker Status Indicator kit?
I'm also thinking about getting the extended mag release since my hand is fairly small.
Also on the AGI Video the guy used "slave" pin.....are these necessary and if so where do you get them.
Thanks for any help and ideas