First update your phone using pc companion or seus to Build number 2.1.1.A.0.6.
Then root your phone using SuperOneClick.
After install CWM recovery http://forum.xda-developers.com/showthread.php?t=1105745
And only then, carefully reading all instructions, try to flash this rom.
Hope it helps
Now my phone alredy update to 2.1.1.A.0.6. by flashtool,before update to 2.1.1.A.0.5, i use super one click root but show busty box not install in flashtool, now i use flashtool root my x10 it show busybox v1 .19.0(2011-08-14 23:46:58CDT) multi-call binary.
After root,what me need to do,i dont understand about this step
Root and CWM recovery already installed (flash it from here)
Latest 2.1.1.A.0.6/2.1.1.C.0.0 SE firmware / Baseband: M76XX-TSNCJOLYM-53404015 due to kernel dependencies. Check this once and twice. There is no point to proceed if you don't have this.
What mean CWM recovery already installed ?Is that i need download CWM-recovery-126.96.36.199-r1-MiniCM and extract bin&sbin file to system?META-INF file need copy or not?