Changing verb tense in a quote after ellipsis

I am using a block quote in my manuscript. The sentence starts off something like this:

Our approach provides a general procedure to deal with this problem by
using...

The block quote is a bit long and I'd rather cut it down to:

Our approach [...] uses...

but now I've changed the tense of using to uses. Is this appropriate? Do I need to make this clear, as in us[es]? That looks really bad.

What is the preferred way to deal with a change in verb tense created by the use of ellipsis?

Answer

Yes, the formally correct way to indicate that you have changed a direct quotation is by using brackets, but I would use them around the whole word you changed, like so:

"Our approach ... [uses] blah blah blah."

As StoneyB points out in the comments below, some styles prefer you to put the "..." in brackets as well, so it's clear that they weren't part of the original quotation. This does not appear to be universal, but should be equally acceptable.

"Our approach [... uses] blah blah blah."