I know from my own experience that many statues are still up, at least in Berlin (for example the Marx and Engels statue near the Rathaus, and the Ernst Thälmann statue in Ernst-Thälmann-Park) and there are still roads, parks and railway stations named after socialist figures (Karl-Marx-Allee; Karl-Liebknecht-Straße; Rosa-Luxemburg-Platz, and so on).

So I have a couple of follow-up questions: is there a pattern to the monuments that were taken down/renamed? For example, were certain figures removed whilst monuments to others retained? Is there a geographical element, so certain cities/regions kept more of the old monuments?

Many of them are still standing to this day. The best and most prominent examples are the Soviet War Memorial in Treptower Park, Berlin, which is absolutely massive and in a way beautiful. Another good example are the tanks parked at Brandenburger Tor, which have been in the local news a lot as tensions with Russia has led to calls for removing these Tanks from the place that is a symbol of German unity (and it's next to parliament). A final example I know of was a huge statue of Lenin also in Berlin. This was dismantled and buried, someone rediscovered it not too long ago.

Basically the Germans deal with their past more than other countries, embracing it and remembering it, the ugly bits too. Also a large percentage of the population was born in the GDR and have positive memories as much as negatives. The way statues/monuments were dealt with reflects this so you will find one or two monuments in every major East German city while the majority will have been removed.