Making weep holes in a retaining wall

[Jak]

I need to make some weep holes in this retaining wall. I’m not a bricklayer or anything but have the basic tools. I was going to chisel out one brick and replace it with a half brick every few feet but then realised the wall is 2 bricks thick. The second image is how it is on the neighbors wall adjoining. Any suggestions appreciated. Cheers 

[Moonshine]

how about, Hire a meaty core drill with bit of required diameter, drill holes, and morter in a plastic pipe in the new hole.

[Declan52]

Just use a long drill bit and drill a perp, vertical motar join between the bricks, out on the  outside so it looks nice.  It will burst out on the inside though.  

[MarkyP]

will the new weep holes do anything? I've often seen these on retaining walls and wonder whether they really serve any purpose. I would think they might perhaps in conjunction with a french drain, or some other means to create a space for liquid water to pool.

[PeterW]

35mm core drill hired for the day and it will do it with ease. Then push in some lengths of black waste pipe and job done. Every 6-900mm will be fine.