We want to be able to override the default richtext processing and link resolving in DXA Java 1.7.

I am a bit lost with how the Spring configuration works, but it looks like there are Spring @Configuration class(es) in the DXA framework which do component scans to pick up default TridionLinkResolver and DefaultRichTextProcessor.

Given these Configuration classes are embedded in the framework and I don't want to change the code and build my own DXA version, how can I change the configuration to pick up my own LinkResolver and RichTextProcessor components?

Further to this, I actually only want to make minor tweaks to the behaviour of the default TridionLinkResolver and DefaultRichTextProcessor. However it seems that these classes contain mostly private methods, which cannot be overridden. Is there some way I can elegantly extend them without having to duplicate the source code (and thus making maintenance and upgrades troublesome)?