Proper procedure to change route advertisement

Thank you all for the help from ANS, MCI, BBN people.
The trafic start flowing to/from ANS network.

To recap my correspondense to them:

the proper way to change route advertisement
from /20 to /19:

first add route object /19 to RADB
advertise the new route /19
wait until it is propagated to the whole internet ( 3 days )
delete the old route object /20
stop advertise the old route /20

by doing this there should be minimal unreachable network.

any comment, suggestion ?

Thank you again for your help.

Tony S. Hariman
Tel: +62(21)574-2488
Fax: +62(21)574-2481