Reflash 9235LE issues

I’m hoping an expert (which I definitely am NOT) could advise me what is the most expedient way for an amateur to reflash a 9235LE mit XPe. Reason for the proposed reflash is that it appears to be locked out of Administrator (ie it totally ignores the ‘shift’ key during startup or shutdown) & according to what I’ve read eleswhere on this fine site, the solution is to reflash.

OK now, this device tells me during bootup that its PXE enabled and has 256Mb RAM so it appears WSI is a possibility. On the other hand, I notice from other postings here that NetXfer is the tool of choice for some at least. There are plenty of spare computers lurking around here (take choice of various FreeBSD / Solaris SPARC / the odd linux / Windows of assorted vintages from 98 to Vista) plus a heap of other networking technology, so no shortage of machinery to setup DHCP / FTP / etc etc. Question is what should I try first ?? (main objective to do the job with minimum chance of bricking the device)

Second question, there appears to be three different firmware files that suit, 9235LE (EMEA/Intl Builds, 256MB) 153489-09.exe v2.1 SP1 B329, 9235LE (U.S. Builds, 256MB) 153489-08.exe v2.1 SP1 B328, and
9235LE (U.S. Builds, 256MB) 153489-01.zip v1.0 B247
None of the firmware choices for a 256Mb device ae specifically for Australia, although I cannot imagine a thin client knowing or caring what language firmware is used. There are Australian files but only 192Mb ones which don’t appear to be suitable for a 256Mb device.

Third question, how do I go about installing SP2 ?? The Wyse site does list a file for SP2 but I think its only a daylight saving patch. Is there some other witchcraft involved in going from XPeSP1 to XPeSP2 ??