Vertex Help - Two Small Parts

[BRSTMason]

I have tried many programs to remove certain vertices, and can't seem to do it without massive glitches even when following tutorials fully, so I came here for help to see if someone could do it.

I only need help on my Eliwood V2.5. I just want the collar removed since it clips a ridiculous amount, and the yellow X on the back removed since it shouldn't be there. They are in polygons 0 and 1. If anyone is willing to do that, it brings it to a final V3, and I would be very grateful and willing to do some BRSTMs in return.