MATLAB How do I pass a signal into a low-pass filter in matlab?
An FIR-filter with windowing would work well in this case. Refer to the following link to see how different orders of FIR filters (for low-pass, band-pass and high-pass) can be implemented:
https://www.mathworks.com/help/signal/ref/fir1.html

The type and degree of windowing will also strongly impact the design of your low-pass filter:
https://www.mathworks.com/help/signal/ug/windows.html