I have heard that freezing the parts will assist in removing the glue.
Having not attempted this myself you may want to wait for additional comments prior to attempting.
http://www.whitearmor.net/forum/topic/25919-dianas-rs-props-build-anh-stunt/
You may want to review the above mentioned build thread...
Some of your answers may be contained for you there.
Best of luck!!
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Arrange them with blue tape on the back then place the Velcro piece on the inside of the helmet once you have them set.
Rather easy and comfortable as well...
Inspirational build to this stage!! WOW!
Note: The break in the "S-Trim" is toward the front of the helmet position in the middle of the vocoder.
Nicely done!!!