Here's HI-2 from HI-10 in nine steps:

 
 



 

        1. CCpqCrCCCspCqtCpt                                        [HI-10]
D1.1 =  2. CpCCCqCrsCCtCCCurCsvCrvwCCrsw
D2.2 =  3. CCCpCqrCCsCCCtqCruCquvCCqrv
D3.1 =  4. CCpqCCCrsCCpqtCst
D3.2 =  5. CCpCCqrCstCCrsCpCrt
D4.1 =  6. CCCpqCCCrsCtCCCurCsvCrvwCqw
D5.4 =  7. CCCCpqrsCCpqCCCpqrr
D6.5 =  8. CCCpCqrCCsCCCtqCruCquvCwCCqrv
D3.7 =  9. CCpqCCCrCCCspCqtCptuu
D8.9 = 10. CpCCqrCCCsqCrtCqt                                    [HI-2]

 
Dolph Ulrich, 2007