I wrote this guide for somebody else:
I figured out how to use it. You can also try using MetaChanger which is in English, although it didn't work for me.
1. Install LMB from Cocricot's website, or just google it. I'm assuming you know how to install mods.
2. Open your game up once it's installed so the config files can be created (\.minecraft\config)
3. In LotMetaBlockMod.cfg, change everything that's "false" to true.
You're supposedly able to change the hotkeys but it didn't work for me.
The default hotkeys, however, are on the forum where you downloaded it.
Use google translate, but in my experience there are really only two
features you need.
4. In LotMetaBlockMod_Server.cfg, set everything "false" to true again.
4b. In the same config, copy and paste, or write, all the id's you want
to modify. At this point, if you don't know what the metadata is, it's
simply an id that alters the appearance of a block, at least in this
case. Now, there are hundreds of ids in MC, and not all of them are
modified in Cocricot. So go to http://cocricot.pics/catalog.html
and copy the "base" number. For example, if you see "20:3," just copy
and paste "20." The same goes if you see "126:5," just copy 126. Make
sure these numbers are IN ORDER. Even if there's no proper number before
it. For example, if you copy 140 and the only numbers that are on that
list already are 135 and 180, you paste 140 in between 135 and 180. Do
that for all things in the catalog.

In game:
This RP modifies the appearance of already existing blocks in game. So
without doing anything, you won't see the mod. Now, choose a block
that's modified by Cocricot. For example, the cobweb can also turn into a
guitar. What you need to do is hold R (default), and use your scroll
wheel. You should see a number above the item in your inventory go from
0-15. In this case, the guitar's id is 9. Pay attention to the catalog
because it says you'll need to place two of these cobwebs vertically to
get a guitar. You'll need to experiment with some because it's not clear
how they work in game.
You can also change items directly by using the Z key while aiming at
the item you want to change and having the item you want to change it
into in your hand. For example, if you want to change a patch of dirt
into stone, simply put the stone in your hand and press Z while aiming
at the dirt. This saves you time b/c you don't need to dig and place.
Also, this is useful for some props such as the mushrooms. It's
difficult or even impossible to do so vanilla, so you'll need to place a
random block as a placeholder and press Z. For example, if you want to
place the beer on a table, you'll need to first get the mushroom in your
hand and switch the id to 4. Next, place a random block on top of the
table and with the mushroom in hand and aiming at the block, press Z.

The developer said the next update will not require LMB because she's making the blocks into its own individual thing.

Hello, I just want to ask you solved it right? I want to install it too and its really hard to understand how to the LotMetaBlock installation gives me Tons of confusion and trouble! Thanks :D