Oracle CRS 10.1 didn’t provide any straightforward way to change to change a single property of a resource. Assume you need to change check interval of a VIP resource from standard 60 seconds to 10 seconds. The steps are below.

• Create .cap file with properties – “crs_stat -p ora.node1.vip >/tmp/ora.node1.vip.cap”
• Edit /tmp/ora.node1.vip.cap to change line CHECK_INTERVAL=10
• Load .cap file back into CRS – “crs_register ora.node1.vip -dir /tmp -u”

Well not difficult but I was always wondering why not to provide a simple command-line option to change a single property. Our Oracle-God, probably, heard prays of DBA’s and added one improvement in 10.2 - crs_register has a new option -update to set some of attributes.
The format is -update [options] [-o options]

I am probably not as smart as developer and/or product manager who decided to split options in two groups - I failed to understand the reasoning behind… I guess as usual to make it tough to learn so that it keeps us in the job.

Anyway to change hosting nodes is “-update -h ” and to change check interval is “-update -o ci=10″. So instead of procedure described above you would use:
crs_register ora.node1.vip -update -o ci=10.

RTFM from more details.