Help on transforming between native space and MNI space

I'm new to a project on neuroimaging. I've figured out what I need to do to get the output but I am struggling to get the images to the right space. I have the DICOMs and .nii files for my scans and I need to convert them to MNI 2009b nlin asym space. I have been working with Lead DBS and SPM for things but it hasn't worked. I know this is possible through FSL but I've never used this before and I'm not sure how to convert to BIDS.

My background is in clinical neuroscience so I have limited programming knowledge