LimeSDR-USB FPGA Capacity issue

I want to place some of my custom modules inside the FPGA startup code provided (

I add them in and after I run synthesize + place & route, I realized that the start-up codes plus my custom modules require more logic elements than the maximal amount that Cyclone IV EP4CE40 could provide (54901/39600).

I saw some posts in community such as removing parts that we do not need (, which might also be helpful in my case. But I am wondering if there are any other solutions/suggestions to let my custom modules fit in the FPGA.

Thanks in advance.