Docbook 5 DTD questions

Hello,

Currently we use Docbook version 4.2. I would like to upgrade to version

5. Unfortunately,our XML editor does not support Relax NG so we have to

continue using a DTD. We also want to upgrade our XSLT stylesheets to 

version 2.0.

My questions are the following:

According to the Docbook V5.0 Transition Guide, if I use the DTD, I should

still "validate my documents against the 

RELAX NG schema before further processing." 

1)I am assuming that further 

processing refers to using the XSLT stylesheets - is this

correct?

2) What is the best way to customize both the Relax NG Schema and 

the DTD? Is it possible to customize the Relax NG schema

and then run a script to create the corresponding DTD?

3)Are there any instructions for customizing the Docbook 5 DTD? The 

instructions in the Transition Guide and the Definitive Guide are

for the Relax NG schema. For example, how can I remove an element?

For example, I've been trying to remove the footnote element using the

following, but this does not appear to work:

<!ELEMENT footnote "IGNORE">

<!ATTLIST footnote "IGNORE">

Thank you,

Kate