Some what ignorant when it comes to ponds

Son in law/daughter have about a 1-2 acre pond on their land , seems kind of shallow and has some weeds and crap in edges and about half way across pond

Best I can tell the deepest part at dam is about 6-7’


Have a buddy with excavator that said he could dig it out and make it deeper and maybe even enlarge it some


About only knowledge I have is what I have read and same for SIL

Any guidance on this would be appreciated ,looking at doing this sometime this spring early summer