I am not sure if you can edit the existing OTD suplpied with the package. Also, you cannot edit all other OTDs which are based on external sources like DB OTD, DTD OTD, XSD OTD etc. It's because you have to change the external system and then create the OTD again.
However, work around to your problem can be:
create a User Defined OTD and use this HL7 OTD as Template.
Again, there should be solid reason for you to edit the existing fields as you should not be deviating from standards. The product supplied libraries are standards. Hence, you cannot achieve editing existing fields in the HL7 OTD.
If you still need to edit field, only option is to create a user defined otd and created all fields manually.
Hope this helps.
Speaking from JCAPS 5.1.2 perspective; the supplied library OTD抯 are read only; however you can copy them to your project folder and modify them any way you see fit. This will work with the segment OTD抯 like MSH, EVN, etc., but it will not work with message OTD抯 like ADT_A01, etc. because they are referencing read only segment OTD抯.
If you want to use an OTD from the library but make changes to it; in the Enterprise Explorer (project explorer) window, expand Sun SeeBeyond -> OTD Library -> HL7 -> <your favorite version>, right click on the OTD, and select copy. Right click on your project folder and select paste. Do this for every segment you want to add to your project.
Open the OTD's in your project folder and modify.
PS. I have interfaces to/from 25 different companies?products; every one of them claiming to be HL7 compliant. And, not one of them follows the standard precisely to the letter. So, I end up tweaking every one of my OTD抯 a bit.
we are in the same situation.. i got to know how to tweak the OTD. thouggh the otd's are copied to the current project, they are still not ediatble. to edit a segment we need to copy the corresponding segment from the library to the current project and import them as external templates and use them.