diff --git a/book/_config.yml b/book/_config.yml
index 99ea80d..02e26d1 100644
--- a/book/_config.yml
+++ b/book/_config.yml
@@ -11,8 +11,6 @@ html:
   baseurl  : "https://teachbooks.io/manual/"
 
 sphinx:
-  local_extensions:
-    include_remove_yaml: _ext/
   extra_extensions:
   - sphinx_inline_tabs
   - sphinx.ext.imgconverter
diff --git a/book/_ext/include_remove_yaml/__init__.py b/book/_ext/include_remove_yaml/__init__.py
deleted file mode 100644
index a6181f5..0000000
--- a/book/_ext/include_remove_yaml/__init__.py
+++ /dev/null
@@ -1,33 +0,0 @@
-from __future__ import annotations
-from sphinx.util import logging
-logger = logging.getLogger(__name__)
-
-def _strip_yaml(lines: list[str]) -> list[str]:
-
-    if not lines:
-        return lines
-    for ix,lines_set in enumerate(lines):
-        new_lines = lines_set.splitlines()
-        if new_lines[0].strip() != "---":
-            continue
-        # yaml front matter detected
-        # find closing delimiter
-        index_end = 1
-        for i in range(1, len(new_lines)):
-            tok = new_lines[i].strip()
-            if tok == "---":
-                index_end = i
-                break
-        new_lines = new_lines[index_end+1 :]
-        lines[ix] = "\n".join(new_lines)
-    return lines  # no closing delimiter -> leave unchanged
-
-def on_include_read(app, docname, path, content):
-    # content is a list[str]; modify in-place
-    new = _strip_yaml(content)
-    if new is not content:
-        content[:] = new
-
-def setup(app):
-    app.connect("include-read", on_include_read)
-    return {}
diff --git a/book/intro.md b/book/intro.md
index c2739e3..165c9f7 100644
--- a/book/intro.md
+++ b/book/intro.md
@@ -1,8 +1,3 @@
----
-file_format: mystnb
-kernelspec:
-  name: python3
----
 # TeachBooks Manual
 
 This manual is primarily designed for and by teachers for use in education, but should be a useful resource for anyone interested in creating and collaborating on a TeachBook: a <a href="https://jupyterbook.org/v1/"><img  style="display:inline-block; height:1.5em; width:auto; transform:translate(0, -0.15em)" src="images/logo-wide.svg" alt="Jupyter book v1"> v1</a> using the <a href="https://www.sphinx-doc.org/"><img  style="display:inline-block; height:1.5em; width:auto; transform:translate(0, -0.15em)" src="images/sphinx-logo.svg" alt="Sphinx logo"> Sphinx backend</a> with additional editing tools and book features. Our aim is to provide a simple way to start book-making for new users (it only takes 10 clicks!), ease the editing process for anyone, and provide additional features developed for education-purposes. We hope you find this resource useful and refer back to it often.
diff --git a/requirements.txt b/requirements.txt
index 946f15a..c7b9259 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,8 +1,8 @@
-# teachbooks == 0.2.3
-git+https://github.com/TeachBooks/TeachBooks@issue-127
+teachbooks == 0.2.3
 sphinx-inline-tabs
 
 git+https://github.com/TeachBooks/TeachBooks-Favourites
+sphinx-gated-directives
 
 teachbooks-sphinx-grasple
 
@@ -11,8 +11,4 @@ sphinx-apa-references
 # For executing Jupyter Notebooks
 myst_nb
 numpy
-matplotlib
-
-sphinx-tudelft-theme == 1.2.1
-
-git+https://github.com/TeachBooks/Sphinx-Gated-Directives
\ No newline at end of file
+matplotlib
\ No newline at end of file